This article is more than 5 years old. Information may no longer be current.
Molecular differences found between tumors of younger, older CRC patients
Click Here to Manage Email Alerts
Tumors in younger colorectal cancer patients may have molecular differences related to epigenetics compared to the tumors of older colorectal cancer patients, according to research presented at European Society of Medical Oncology’s European Cancer Congress.
To determine if early-onset colorectal cancer has molecular distinctions compared to average-onset CRC, Andrea Cercek, MD, an assistant attending physician at the Memorial Sloan Kettering Cancer Center, and assistant professor of medicine at Weill Cornell Medical Center, New York, and colleagues analyzed genetic mutations in tumors from 126 patients aged younger than 50 years and 368 aged 50 years and older.
“Interestingly, we found a different frequency of mutation of genes known to be cancer-causing in the different age groups,” she said in a press release.
The CRC patients were recruited from two cohorts, including patients treated at Memorial Sloan Kettering and patients from the U.S. National Cancer Institute’s Cancer Genome Atlas, who were analyzed for somatic mutations, gene expression and DNA methylation using standard genomic sequencing techniques. The researchers excluded patients with hypermutated tumors or microsatellite instability, then compared mutation profiles and methylation between age groups.
They found different mutation frequencies between age groups among ATRX, DIS3, RAD52 and SMO genes, which are known to be associated with carcinogenesis. They also found different DNA methylation profiles between age groups.
“In the early-onset group, we found that 154 genes were undermethylated,” Cercek said in the press release. “We also found that an increase in methylation went hand-in-hand with an increase in age among the younger patients, and that this intensification was beyond that which would occur naturally in normal tissue [P = .01]. Finding such a distinctive molecular make-up in this group encourages us to believe that we may, in the future, be able to tailor treatments to them and attempt to prevent or slow down these processes in order to improve outcomes for them.”
Raising clinical awareness of the rising frequency of younger-onset CRC is important because younger patients are sent for early CRC screening less frequently than older patients, Cercek said in the press release. The findings of this study are important because the only difference in the therapies used to treat younger CRC patients is that they are often treated more aggressively, she added.
“We hope to be able to continue research on the molecular and epigenetic characterization of tumors from younger-onset CRC patients in order to be able to develop better therapies for them, and improve their overall survival as well as their quality of life,” she said in the press release.
“While we have indications that screening for CRC in an older age group is important, this is not the case in a younger general population,” Peter Naredi, MD, PhD, the ECCO scientific co-chair of the Congress, who was not involved in the research, said in the press release. “Therefore, it is important to identify younger persons with a higher risk of CRC, and … Cercek’s epigenetic analyses are an important step towards this. As … Cercek also says, identifying specific genetic patterns in CRC tumors in younger patients may lead to better treatment options.” – by Adam Leitenberger
Reference:
Ben-Aharon I, et al. Abstract 2189. Presented at: European Cancer Congress; September 25-29, 2015; Vienna.
Disclosures: The researchers report no relevant financial disclosures.